Noiseless typewriter



- Nov. 10, 1936. H. BATES NOISELESS TYPEWRITER 1 Filed May 19, 1936 2 Sheets-Sheet l NOV. 10, 1936. H, BATES NOISELESS TYPEWRITER Filed May 19, 1956 2 Sheets-Sheet 2 Patented Nov. 10, 1936 UNITED STATES PATENT OFFICE N OISELESS TYPEWRITER Application May 19, 1936, Serial No. 80,602

20 Claims.

This invention relates to improvements in socalled quiet or noiseless typewriters, and more particularly to improvements in typewriter movements of the type disclosed in the patent to R. Atti, No. 1,952,192, dated March 27, 1934, and in my application Serial No. 730,902, filed June 16, 1934.

The primary object of the present invention is to provide a type bar and associated mechanism that can be adjusted for a minimum of sound in the impact of the type on the paper.

Another object is to furnish improved type bar operating means utilizing an eccentric, which is, in operation, quiet.

Still another object is to combine the eccentric with spring means for rapidly changing the position of the eccentric.

A further object is to supply a quiet or noiseless typewriter of simpler and more nearly silent operation than the conventional machines now on the market.

A still further object is to provide a type bar having a means by which the force of the impact of the type will be uniformly maintained, thus insuring a uniform and hence a superior quality of printing, and also a means by which the force of the impact of the type may be regulated from light to heavy for manifolding or other purposes.

With the foregoing objects outlined and with other objects in view which will appear as the description proceeds, the invention consists in the novel features hereinafter described in detail, illustrated in the accompanying drawings, and more particularly pointed out in the appended claims.

In the drawings,

Fig. 1 is a side elevation of a typewriter action showing the typewriter frame and platen diagrammatically and with the key bar and type bar forming parts of the typewriter action at rest.

Fig. 2 is a similar view with the key bar slightly depressed and showing the toggle in slightly elevated position on its up stroke.

Fig. 3 is a like view with the key bar fully depressed and the toggle in its uppermost position.

Fig. 4 is an elevation showing the position of the parts with the toggle straightened out on its downward movement, and illustrating the manner in which the toggle in descending forces the type bar against the platen.

Fig. 5 is a similar view with the parts at rest after they have returned to normal position.

Fig. '6 is a top plan view of the action showing one form of adjusting means for limiting the upward movement of the toggle.

Fig. 7 is a perspective view of a detail showing the shiftable eccentric support for the toggle.

In order that the invention may be clearly understood, I shall explain that from the beginning my basic idea has been to obtain quiet or noiseless operation in a typewriter, not silence. It is not likely that a writing machine could be made silent in the sense of being soundless. But every action of a typewriter, including the impactof the type, can be made quiet or noiseless.

In certain machines now being marketed, the type prints with a relatively quiet pressure stroke because when the type bar attains a position in close proximity to the printing point, its further action depends upon the movement of a small weight back of it which accelerates it in such a way as to press the type against the paper. In such machines, the final movement of the small weight back of the bar is not mechanically positive since if the operator does not strike the key sharply, the weight may not gain sufficient momentum to cause the type to print. There also may be a lack of uniformity in the printing if the type keys are not all struck by the operator with the same force and in the same way.

In my invention, I cause the type bar in its movement toward the platen to stop momentarily, recede, and then to go forward again by an action which is positive and subject to mechanical control. Stated differently, there are three general movements of the type bar before the type printsit starts forward, then it stops and recedes before the type has reached the 3 printing point, and finally it goes forward again and presses the type against the paper. It is the final action of pressing the type against the paper by a means which is subject to mechanical control that makes it practical to obtain quiet printing and provides other distinct advantages which I shall describe briefly.

With my invention I obtain uniform printing. In nearly all typewriters now being used, the harder and more sharply one strikes the keys the heavier will be the impact of the type. In my development, the impact of the type will be the same whether the key is struck lightly or heavily, slowly or sharply, because it is not regulated by the force or the manner of the blow but by the final downward action of a toggle which set in motion by, but operates independently of the type key, all of which results in a mechanical uniformity of impact and of printing.

By an adjusting means which causes the type bar to recede a longer or a shorter distance away from the platen before it prints, it is possible to make more and better carbon copies because the farther back the type bar recedes, the harder is the ensuing impact of the type itself.

In the accompanying drawings, I have illustrated a single typewriter action, but it will be understood that this mechanism will be duplicated for each key of the typewriter.

Referring to the drawings, 8 designates a key bar or lever which is pivotally mounted on a horizontal axle 9 carried by the frame IQ of the machine. This bar is guided in movement by any suitable means such as a guide ll supported by the frame, and the front end of the bar has a conventional key 12. Any suitable means such as a coil spring I3 serves to yieldingly hold the bar in contact with a suitable cushioning member such as a rubber disc M.

A typebar or lever is pivotally mounted on the frame by means of a horizontal axle l6 and the type I! at its upper end is adapted to strike the conventional inked ribbon I8 to make impressions on a sheet or sheets of paper l9 fed by the usual platen 20.

Means are provided for operatively connecting the typebar and key bar, and in accordance with the present invention, this means consists of a link 2| and a toggle 22. The link has its lower end pivotally connected at 23 to the key bar and its upper end pivotally connected at 24 to the forward or outer end of the toggle link 25. The other toggle link 26 is pivotally connected at 21 to the typebar, and the toggle links have their inner ends pivotally connected by a pin 28.

In accordance with the present invention, the forward end portion of the toggle link is rotatably supported by a disc-shaped eccentric bearing 29 which in turn is supported by a stub shaft 30 that rotates in a suitable bearing in the frame and is eccentrically arranged relatively to the axis of the disc 29.

As best shown in Fig. 7, a specially shaped relatively thin member 3| is rigidly united with the disc, and it has a wing or projection 32 projecting outwardly beyond the periphery of the disc. It will be understood that if the member 3| is rotated about the axis of the shaft 30, the disc 29 will also be shifted about this axis, and in this way the bearing for the toggle link 25 can be moved toward or away from the platen. In order to shift this bearing, the link 25 has a pair of projecting pins 33 and 34 which cooperate with the wing 32 to shift the eccentric support during the upward and downward movements of the toggle. Obviously, when the toggle is moving upwardly, the pin 33 will engage the wing 32 to cause turning of the eccentric about the axis 38, and this will result in shifting the bearing of the link 25 toward the platen. On the downward movement of the toggle, the pin 34 will engage the wing and return it to normal position.

For the purpose of assisting in the shifting of the eccentric bearing and holding the member 3| in its different positions of adjustment, the member 3| is provided with a pair of abutment surfaces 35 and 36, either of which can be engaged by a leaf spring 3'! mounted on a suitable support 38 on the frame.

By providing the eccentric bearing for the link 25, even though the toggle straightens out in its upward movement, it will not force the type into contact with the platen, but on the downward movement, due to the shifting of the eccentric support, the toggle in straightening out will cause the type to strike the platen.

In operation, it will be understood that the depression of the key [2 does not cause the type to strike the platen. Such movement simply results in the raising of the toggle to its highest position. However, the toggle in moving to such position will cause its pin 33 to engage the wing 32 and shift the eccentric bar in a counter-clockwise direction about the axis 30, resulting in moving the axis of the disc 29 nearer to the platen 20. Then, as the toggle descends, it, in straightening out, will force the type into contact with the platen. After the toggle has passed dead center in descending, its pin 34 will engage the wing 32 and again shift the eccentric bearing back to its normal position. Of course, the movement of the eccentric bearing will be assisted by the spring 37, for when the point of the angle between the surfaces 35 and 36 passes dead center, the leaf spring 3'! will cooperate with one or the other of the abutment surfaces to snap the eccentric bearing into one or the other of its positions of adjustment.

The height to which the toggle is raised will determine the force of the blow with which the type strikes the platen. Obviously, if the toggle is raised to its uppermost limit, in descending it will cause the type to strike the platen the hardest low, whereas if the toggle is not permitted to go to this height, the force of the blow will be less. Any suitable means may be employed to adjustably control the elevation of the toggle. For example, a plate 40 may be pivotally mounted on the frame by means of a screw 4|. The inner end of this plate is preferably beveled or pointed, as shown at 42, and this end will cooperate with the link 25 to determine the height to which the toggle can be raised. The plate acts as a stop for the link 2 5, and by shifting the plate about its axis, the upward movement of the toggle can be halted at any elevation desired.

From the foregoing it will be understood that I have provided improved means whereby the action of the typebars is not caused by the depression of the key bars. Such depression simply raises the toggle, and the toggle, in descending, causes the movement of the key bar into contact with the platen. It will also be understood, and as may be readily seen from Fig. 3, that the upward movement of the toggle brings the type into close proximity to the platen without the type actually striking the latter, and then, when the toggle descends, the typebar moves only a relatively short distance to'cause the type to sharply i strike the platen. This improved action results in a quieter typewriter.

It will thus be appreciated that in accordance with my invention, there are three general movements of the typebar l5 before the type prints it starts forward from the position shown in Fig. 1, stops and recedes as shown in Figs. 2 and 3, and finaly goes forward again and presses the type against the paper, as illustrated in Fig. 4.

It should be noted therefore, that the action is altogether different from the generally accepted movements of the bar of a typewriter. In conventional machines now on the market, and others in the process of development, the action of the toggle is one-way-that is, the printing is accomplished either by the mere straightening out of the toggle, or by the bar straightening out and a weight doing the printing. My mechanism changes the generally accepted movements or results of printing, for, while all other mechanisms cause the bar to print on the downward pressure of the key l2, my mechanism prints in an opposite manner-as the key is released, but the action of the parts is so rapid, there is hardly a perceptible difference.

In accordance with my invention, the printing is accomplished after the key l2 has been released by the toggle straightening out as it passes through the center on its downward movement. In other words, the toggle, on its upward movement, passes above the center, and then, so that it will not go farther up than desired, it is stopped by the adjusting member 40, the shock spring l3, or both, and as soon as it is stopped, it starts on its downward course, pulled through the center, or actuated downward by the spring l3. Of course, the toggle having been stopped in its upward movement, momentum helps pull the toggle through the center on the descent, but the spring l3 really acts to stop the toggle, start it downward, and pull it through the center.

While I have disclosed what I now consider to be a preferred embodiment of the invention, it will be understood by those skilled in the art that changes may be made in the details disclosed, without departing from the spirit of the invention, as expressed in the claims.

What I claim and desire to secure by Letters Patent is:

1. In a typewriter, in combination, a platen, type means movable toward and away from the platen, key means, means operatively connecting said type means and key means and including a toggle, eccentric pivot means for said toggle normally maintaining the toggle in such position that said type means upon application of pressure on said key means will be advanced within close proximity of the platen as the toggle rises from a lower position to an upper position, and means for shifting the eccentric pivot means toward the platen to cause the toggle in descending from its upper position to the lower position to move said type means against said platen.

2. In a typewriter, in combination, a platen, a typebar movable toward and away from said platen, key means, means connecting the typebar to the key means and including a toggle, eccentric pivot means for said toggle normally maintaining the toggle in such position that said typebar upon application of pressure on said key means will be advanced within close proximity of the platen as the toggle rises from a lower position to an upper position, and means for shifting the eccentric pivot means to cause the toggle in descending from its upper position to the lower position to move said typebar against said platen.

3. In a typewriter, in combination, a platen, type means movable toward and away from the platen, key means, means operatively connecting the type means and key means and including a toggle, shiftable eccentric pivot means for said toggle normally maintaining the toggle in such position that said type means upon application of pressure on said key means will be advanced within close proximity of the platen as the toggle rises from a lower position to an upper position, means for shifting the eccentric pivot means to cause the toggle in descending from its upper position to the lower position to move said type means against the platen, and a spring cooperating with the pivot means for yieldingly holding the pivot means in its different positions of ad justment.

4. In a typewriter, in combination, a platen, type means movable toward and away fromthe platen, key means, means operatively connecting the type means and key means and including a toggle, shiftable eccentric pivot means for said toggle normally maintaining the toggle in such position that said type means upon application of pressure on said key means will be advanced within close proximity of the platen as the toggle rises from a lower position to an upper position, means for shifting the eccentric pivot means to cause the toggle in descending from its upper position to the lower position to move said type meansagainst the platen, and a spring cooperating with the eccentric pivot means to assist in shifting said pivot means.

5. In a typewriter, in combination, a platen, a typebar movable about a horizontal axis and shiftable toward and away from the platen, key means, means operatively connecting the typebar and key means and including a toggle, shiftable eccentric pivot means for said toggle normally maintaining the toggle in such position that said type bar upon application of pressure on said key means will be advanced within close proximity of'the platen as the toggle rises from a lower position to an upper position, and means actuated by the toggle for shifting the eccentric pivot means to cause the toggle in descending from its upper position to the lower position to'move said typebar against said platen.

6. In a typewriter, in combination, a platen, type means movable toward and away from the platen, key means, means operatively connecting the type means and key means and including a toggle, said toggle comprising a plurality of pivotally connected links, the outer end of one of said links being pivotally connected to the type means, shiftable eccentric pivot means supporting the outer end of the other link of the toggle and normally positioned to cause the type means to advance toward the platen but not to contact the latter when the toggle goes from a lower position to an upper position upon application of pressure on said key means, and means for shifting the eccentric pivot means to cause the toggle in descending from its upper position to the lower position to move said type means against said platen.

7. In a typewriter, in combination, a platen, type means movable toward and away from the platen, key means, means operatively connecting the type means and key means and including a toggle, a shiftable eccentric pivot for the toggle controlling the latter and causing the key means to be advanced within close proximity of the platen as the toggle rises from a lower position to an upper position upon the application of pressure on said key means, and means actuated by the toggle for shifting the eccentric pivot to cause the toggle in descending from its upper position to its lower position to move said type means against said platen.

8. In a typewriter, in combination, a platen, type means movable toward and away from the platen, key means, means operatively connecting the type means and key means and including a toggle, a shiftable eccentric pivot for the toggle controlling the latter and causing the key means to be advanced within close proximity of the platen as the toggle rises from a lower position to an upper position upon the application of pressure on said key means, means actuated by the toggle for shifting the eccentric pivot to cause the toggle in descending from its upper position to its lower position to move said type means againstsaid platen, and a spring cooperating with the eccentric pivot for yieldingly'holdingalt'in its different positions; of adjustment;

9. In a typewriter, in combination, a platen, type means movable toward and away from the platen, key means for actuating, the type means,, means operatively connecting the type means and key means and including a toggle, an eccentric pivotal support for they toggle shiftable about a horizontal axis, said support. normally holding the toggle at such a distance from the platen that the type means can be advanced within close proximity of the platen as the toggle rises from a lower position. to an upper position upon application of pressure on said key means, and means controlled by the toggle for shifting the eccentric pivotal support toward the platen as the toggle rises to cause the toggle in descending to move said type means against said platen.

10. In a typewriter, in combination, a platen, type means movable toward and away from the platen, key means for actuating the type. means, means operatively connecting the type means and key means. and including a toggle, an eccentric pivotal support for the toggle shiftable about a horizontal axis, said support normally holding the toggle at such a distance. from the platen that the type means canbe advanced within close proximity of the platen as the toggle rises from. a lower position to an upper position upon application of pressure on said key means, means controlled by the toggle for shifting the eccentric pivotal support toward the platen as the toggle rises to cause the toggle in descending to move. said type means against said platen, and a spring cooperating with the eccentric pivotal support for holding the latter in its different positions of adjustment.

11. In a typewriter, in combination, a platen, a typebar shiftable about a horizontal axis and movable toward and away from the platen, a key lever pivotally mounted for movement about a horizontal axis, means operatively connecting shiftable about a horizontal axis and normally preventing the key bar from striking the. platen when the toggle rises from a lower position to an upper position upon application of pressure on the key lever, and means for shifting the eccentric pivotal support toward the platen to cause the toggle in descending from its upper position to the lower position to move said typebar against said platen.

12. In a typewriter, in combination, a platen, a typebar shiftable about a horizontal axis and movable toward and away from the platen, a key lever pivotally mounted for movement about a horizontal axis, means operatively connecting said type bar and key lever and including a toggle, an eccentric pivotal support. for the toggle shiftable about a horizontal axis and normally preventing the key bar from striking the platen when the toggle rises from a lower position to an upper position upon application of pressure on thekey lever, means for shifting the eccentric pivotal support toward the platen to cause the toggle in descending from its upper position to the lower position to move said typebar against said platen, and yielding means cooperating with the pivotal support to assist in shifting it and to hold the support in its different positions of adjustment.

13. In a typewriter, in combination, a platen, type means movable toward and away from the platen, key means for actuating the. type means,

means operatively connecting the key means and type means and including a toggle, an eccentric pivotal support for the toggle, means actuated by'the. toggle for shifting the pivotal support toward the platen when the toggle moves in one direction and for moving it away from the platen when the toggle moves in the opposite direction, resilient means cooperating with the eccentric pivotal support for holding it in its different positions of adjustment.

14. In a typewriter, in combination, a platen, type means. movable toward and away from the platen, key means, means operatively connecting the type means and key means and including a toggle, an eccentric pivotal support for the toggle movable about a horizontal axis, means actuated by the toggle for shifting said support toward the platen when the toggle is moved in one direction and for moving it away from the platen when the toggle is moved in the opposite direction, abutment means rigidly united with the eccentric pivotal support, and a spring cooperating wit-h the abutment means to assist in shifting the pivotal support and to yieldingly hold the support in its different positions of adjustment.

In a typewriter, in combination, a platen, a pivoted type bar movable toward and away from the platen, pivoted key means, a pair of pivotally connected toggle links, the outer end of one of said links being pivotally connected to the type bar, a third link connecting the outer end ot the other toggle link to the key means, an eccentric pivotal support for the last-mentioned toggle link movable about a horizontal axis, means actuated upon movement of the toggle in one direction to shift the pivotal support toward the platen and when the toggle moves in the opposite direction to shift the pivotal support away from the platen, and means for holding the pivotal support in its different positions of adjustment.

16. In a typewriter, in combination, a platen, a pivoted type bar movable toward and away from the platen, pivoted key means, a pair of pivotally connected toggle links, the outer end of one of said links being pivotally connected to the type bar, a third link connecting the outer end of the other toggle link to the key means, an eccentric pivotal support for the last-mentioned toggle link movable about a horizontal "axis, means actuated upon movement of the toggle in one direction to shift the pivotal support toward the platen and when the toggle moves in the opposite direction to shift the pivotal support away from the platen, means for holding the pivotal support in its different positions of adjustment, the last-mentioned means including abutment surfaces on the support and a cooperating spring.

17. In a typewriter, in combination, a platen, type means movable toward and away from the platen, key means, means operatively connecting the type means and key means and including a toggle, an eccentric pivotal support for the toggle movable about a horizontal axis and having a plurality of abutment surfaces, means actuated by the toggle for moving the support toward the platen when the toggle is moved in one direction and for moving the support away from the platen when the toggle is moved in the opposite direction, and resilient means engageable with said abutment surfaces to assist in shifting the support and for yieldingly holding the support in its different positions of adjustment.

18. In. a typewriter, in combination, a platen,

type means movable toward and away from the platen, key means, means cooperating with said key means and type means for causing the type means to approach but not touch the platen upon depression of the key means and to move the type means into contact with the platen upon release of pressure from the key means, and ad- J'ustable means cooperating with the third mentioned means for controlling the force with which the type means strikes the platen.

19. In a typewriter, in combination, a platen, type means movable toward and away from the platen, key means, a toggle operatively connected to said type means and key means, shiftable pivot means for said toggle normally maintaining the toggle in such position that said type means upon application of pressure on said key means will be advanced within close proximity, but short of the platen as the toggle rises from a lower position through a zone of dead center to an upper position, adjustable means cooperating with the toggle to limit the upward movement of the same, and means for shifting the toggle pivot means toward the platen to cause the toggle in descending from its upper position to the lower position through said zone of dead center to move said type means against said platen.

20. In a typewriter, in combination, a platen, type means movable toward and away from the platen, key means, means operatively connecting the type means and key means and including a toggle, shiftable pivot means for the toggle to cause it to move toward or away from the platen, means actuated by the toggle for shifting said pivot means toward the platen when the toggle is moved in one direction and for shifting said pivot means away from the platen when the toggle is moved in the opposite direction, and adjustable means cooperating with the toggle for limiting the movement of the latter in one direction.

HARRY BATES. 

